Dr. Fukui is interested in studying how the actomyosin cytoskeleton is spatially and temporally organized in the cytoplasm. To pursue these problems, he will employ Dictyostelium discoideum. In this proposal, he addresses: (1) movement and assembly of myosin, in real time, in the cytoplasm of living cells; (2) quantification of vesicle movement in living cells; (3) tactile response of individual cells and the force generation of surface projections; and (4) the organizing center of the actomyosin cytoskeleton. Methods include video microscopy of micro- injected fluroescence-labeled myosin, of the vesicle movement, micro- manipulation of surface projections, and force measurement. He will also study the organization of myosin filaments with rapid freeze and rapid dry electron microscopy. He wishes to study both wild type and genetically engineered mutants.